ROK Navy's Latest Diesel-Electric Attack Sub to Deploy in May

The Republic of Korea (ROK) Navy’s seventh Son Won II-class (Type 214) diesel-electric air-independent propulsion (AIP) submarine, christened Hong Beom-do, will be operationally deployed beginning in May 2018, South Korea’s Defense Acquisition Program Administration (DAPA) announced on January 19.

The sub’s crew has been undergoing intensive training for the past four months, the statement notes, and will soon be ready for its first patrol. The new boat will enhance the ROK Navy’s “underwater operational capability,” which is superior to North Korea’s, the head of DAPA said, according to the press release.

The Hong Beom-do, named after a South Korean national hero, was built by Hyundai Heavy Industries (HHI). The submarine was launched in April 2016. It was the fifth Son Won II-class submarine, a variant of the Type 214 submarine of Germany’s Howaldtswerke-Deutsche Werft, built by HHI under license.

In September 2017, HHI launched the ninth and final submarine of its class under the ROK Navy’s Son Won II-class (also known as KSS-2) acquisition program. Overall, HHI built six KSS 2-class boats, with Daewoo Shipbuilding & Marine Engineering (DSME) assembling the remaining three.

Each Son Won II-class sub measures 65 meters (213 feet) in length and seven meters (22 feet) in width. The boat’s top surface speed is around 12 knots and up to 20 knots when submerged powered by its electric motor.

“With its air-independent propulsion system, built around Siemens polymer electrolytic membrane fuel cells, the submarine can stay submerged for up to two weeks and can dive up to 400 meters (1,312 feet) deep,” I reported elsewhere.

According to senior ROK Navy officers, the Son Won II-class, armed with long-range submarine-to-ground cruise missiles, boasts precision-strike capabilities and can attack ground targets deep inland. (DAPA is working on a new submarine-launched ballistic missile, or SLBM, for its sub force.) The Hong Beom-do is capable of detecting and tracking up to 300 targets simultaneously, according to DAPA.

As I noted elsewhere, South Korea is investing heavily into building up its submarine force:

The recent launch is part of a three-phased naval construction program to build up the ROKN attack submarine force. South Korea currently operates a fleet of nine 1,200-ton Chang Bogo-class diesel-electric attack submarines – a variant of the German Type 209 boat. Under the first phase, the ROKN is planning to upgrade all nine Chang Bogo-class submarines with air-independent propulsion and flank-array sonars over the next few years.

The nine Son Won II-class vessels are part of the second phase of the ROKN’s so-called Korean Attack Submarine program. The third and final phase (and also the most ambitious part of the project) will be the construction of nine indigenously produced 3,000-ton diesel-electric attack submarines – designated KSS-III – equipped with air-independent propulsion and multiple vertical launch tubes from which Hyunmoo-3C cruise missiles with a range of up to 1,500 kilometers can be fired.

The ROK Navy is expected to operationally deploy a total of 18 diesel-electric attack subs by 2019.